PMT High Voltage Power Supply Status - user-web.icecube

MONS, BELGIUM OCTOBER 2003 NOBUYOSHI KITAMURA UW-MADISON / SSEC

PMT High Voltage Power Supply Status

Nobuyoshi Kitamura

University of Wisconsin-Madison


Overview

PMT HV Base Board

PMTDigital Optical Module Main Board(DOMMB)

DigitalcontrolPower

PMTAnodesignal

Digital Interface Analog Interface

Highvoltage


The Three Prototypes

“Old Iseg”—Aug. 2002 prototypes

“New Iseg”—Split ground implemented.

“EMCO”—Passive base approach consisting of three components:Passive base, HV generator, & digital interface.

Jumper pads

Digital interface boardHV generator

Passive base

Ribbon connector

Jumper pads


Photos

EMCO Passive Base“New Iseg”

HV Control Board EMCO HV Generator


Treat Them Equally

Every effort was made to make the DOMMB interface uniform among the three prototypes.


Chronology—2003

Feb. 20 EMCO reps visit UW-Madison

Mar. 11 Iseg head visits DESY / Zeuthen

Apr. 28 EMCO generators (20) and bases (20) arrive

May 9 Operate EMCO generator with DOMMB29 New Iseg bases arrive (8)

June 24 New Iseg bases arrive (22)

July 23-24 LBNL Workshop ”Old Iseg will do!”

Aug. 12 IceCube report on proto evaluation by NK14 Comments on proto sent to Iseg22 Request for technical information from Iseg26 The “crack incident”

Sep. 8 NK report ”Refocus on EMCO”19 Trip to EMCO

Oct. 1 PO for samples (4) sent to EMCO


The Three Prototypes (summary)

Old Iseg or New Iseg?New Iseg with isolated grounds performs badlyNew Iseg with directly connected grounds performs badlyNew Iseg with 1MΩ jumper performs very similarly to Old IsegOld Iseg is cheaper than New IsegOld Iseg consumes less power then New Iseg

Old Iseg

Iseg or EMCO?Both have similar noise levelsVdy1 is fixed in Iseg approachIseg is cheaper than EMCO

Iseg

Trouble with the “New Iseg”


New Iseg--Isolated GroundOutput voltage is very unstable with no ground-connecting jumper

Data by John Kelly(hv_2000_iseg_psl.pdf)

Previously reported at LBNL Workship (July 23-24, 2003)

N. Kitamura 7/23/2003


Connecting Grounds with a Zero Ω Jumper




Comparison using DOMMB ATWD

http://www.ssec.wisc.edu/~kitamura/HVstatus081203/PMTBaseComparisonWithATWD1.pdf




Noise Comparison

All the bases have similar random noise levels observed at the secondary side of the signal coupling transformer.

215 ± 31208 ± 18214 ± 18µVrms

1.12 ± 0.211.26 ± 0.131.22 ± 0.13mVppNOISE AT OUTPUT*

EMCOISEG NEWISEG OLD

*At 50Ω oscilloscope input using a 50Ω cable. 100 nsec window (400 pts.)The scope background is 1mVpp, 190µVrms over 100 nsec.




Overall Comparison

1.12 ± 0.211.26 ± 0.131.22 ± 0.13mVppNOISE AT OUTPUT*

EMCOISEG NEWISEG OLD

~600~260~150COST (US$)

250280130POWER AT MAX OUTPUT (mW)

SCALE WITH OUTPUT

FIXED (600V)1ST DYNODE VOLTAGE

215 ± 31208 ± 18214 ± 18µVrms

*At 50Ω oscilloscope input using a 50Ω cable. 100 nsec window (400 pts.)The scope background is 1mVpp, 190µVrms over 100 nsec.




Thoughts at the End of July, 2003

Select and pursue “Old Iseg”-style design

Need further tests

Must improve communication with vendor

Must examine design details

Conduct Failure Modes and Effects Analysis (FMEA)


Layout Examination

http://www.ssec.wisc.edu/~kitamura/HVstatus090803/Iseg_photos2.pdf




Failure of an Old Iseg Board


Recommended Action

... drop Iseg as our primary candidate of the PMT HV Base board supplier and bring the alternative vendor to our focus.

--NK’s report dated September 8, 2003http://www.ssec.wisc.edu/~kitamura/reports/HVstrategy.pdf

http://www.ssec.wisc.edu/~kitamura/reports/HVstrategy.pdf

http://www.ssec.wisc.edu/~kitamura/reports/HVstrategy.pdf


EMCO High Voltage Corporation

Located in Sutter Creek, California, USA

In HV business for 30+ years

Has delivered twenty (20) each of HV Generator and PMT Base Board

The prototypes performed as specified in all tested parameters

Trip report by NK:http://www.ssec.wisc.edu/~kitamura/reports/EMCO_trip_rpt.pdf

Trip report by George Anderson:http://www.ssec.wisc.edu/~kitamura/reports/Emco%20Meeting%20Report%209.19.03.pdf

http://www.ssec.wisc.edu/~kitamura/reports/EMCO_trip_rpt.pdf

http://www.ssec.wisc.edu/~kitamura/reports/EMCO_trip_rpt.pdf

http://www.ssec.wisc.edu/~kitamura/reports/Emco Meeting Report 9.19.03.pdf


Buying 5000+

Bidding process is necessary

In process:Define / refine specifications


Requirements & Specifications

PMT Modular HV Power Supply ERDHV Control Board Specification Control DrawingPMT HV Base Board Specification Control DrawingHV Generator Source-Controlled Drawing


Requirements Documents

PMT High Voltage Board Requirements Document

(9000-0039*)

PMT High Voltage Power Supply Requirements

Document (9000-0039-01*)

PMT Modular High Voltage Power Supply

Requirements Document (9000-0039-02*)

“Passive Base”

*George Anderson has been maintaining these documents.


Improved Specifications

PMT Base BoardNew pulse-coupling transformer designThrough-hole componentsAdditional RC filter at HV entryImproved output cable attachment

HV Generator“HV_DISABLE” pin is addedModified MON and PROG analog rangeHigher-voltage-rated output cableEliminate GAIN_ADJ trim-pot

HV Control BoardHigher reliability due to fewer components

(delete three ICs)http://www.ssec.wisc.edu/~kitamura/HVReview_091603.htm

http://www.ssec.wisc.edu/~kitamura/HVReview_091603.htm

http://www.ssec.wisc.edu/~kitamura/HVReview_091603.htm


PMT Base Board


Toroidal Transformer

PP’

S

S’

S

S’

P

P’

Old TransformerRG178 coaxial cable

Rated at 1000Vrms

New Transformer22 AWG silicone-insulated bifilar

Rated at 10kV


Toroidal Transformer Response

Temperature = −40oCPMT gain = ~1 x 107

New

Old

nsec

The bifilar transformer performs better!

Each curve is an average over 1000 triggers.

Laboratory HV supply with an EMCO passive base was used.

http://www.ssec.wisc.edu/~kitamura/toroid.htm




Output Cable Attachment

Proposed

Iseg

EMCO


HV Generator

Spec changes:

Change PROG range from 0..4095V to 0..2047V

Change MON range from 0..4095V to 0..2047V

Add “HV_DISABLE” pin (No reliability penalty. Optional usage)

Eliminate GAIN_ADJ trim-pot (No need for absolute accuracy)

Use higher-voltage-rated output cable

Overall simplicity and increased reliability


HV Control Board

Spec changes:

Change PROG range from 0..4095V to 0..2047VEliminates x 2 OP-AMPEliminates –5V power switch

Change MON range from 0..4095V to 0..2047VEliminate 0..4096V REF

Overall simplicity and increased reliability


Tasks Ahead

Test Rev 3 Main Boards with the EMCO passive base / HV generator.

Test new EMCO samples (4) with Rev 3 Main Boards

Have EMCO deliver 60 each of the PMT Base Board and the HV Control Board (including the HV Generator)

Complete specification control drawing for the bid package

Create verification plan


Conclusion

Just as System concluded after the recent PDR, mature in design but weak in verification.